Combine in Playgrounds

Question

I'm inspecting Combine, a new framework by Apple. I created a playground, ran it in macOS Mojave 10.14.5 and Xcode 11.0 beta (11M336w).

Here is my code:

import Combine

struct Article: Identifiable {

    var id: Int
    var title: String
}

final class Data: BindableObject {

    let didChange = PassthroughSubject<Data, Never>()

    var showFavouriteOnly = false {
        didSet {
            didChange.send(self)
        }
    }
    var articles: [Article] = [.init(id: 1, title: "WWDC 2018"),
                               .init(id: 2, title: "WWDC 2019")] {
        didSet {
            didChange.send(self)
        }
    }
}

But it fails with log:

error: Couldn't lookup symbols: Combine.PassthroughSubject.send(A) -> ()

What am I doing wrong?

You can see in the system requirements pane to the right, that `macOS 10.15+` is needed. — ielyamani, Jun 05 '19 at 14:29
@MwcsMac I'm a bit confused as to why SwiftUI, which has the same macOS 10.15+ requirement, works in a playground in Xcode 11 while Combine fails. — jjoelson, Jun 09 '19 at 15:26

score 2 · Answer 1 · answered Jun 11 '19 at 08:13

If you created an iOS playground, then Combine should work even if you’re running Xcode 11 or later on macOS 10.14. If you created a macOS playground, Combine will only work if you are running Xcode 11 or later on macOS 10.15 (Catalina) or later.

If you created an iOS playground, then it’s entirely possible that you have found a bug in Combine (or in the Swift compiler). You can report it at Apple’s feedback site if you like.

score 1 · Answer 2 · edited Nov 11 '20 at 14:13

1

The first version of Xcode 11 beta does not have Combine working, it has been stated in the release note.

You should download the second Xcode 11 beta (11M337n)

edited Nov 11 '20 at 14:13

hybridcattt

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answered Jun 26 '19 at 05:12

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+1: Also, certain beta versions seem to have breaking issues as well – e.g. beta 4 likes to crash with Combine @Published properties... your best bet is to ensure you're always on the latest beta. – JRG-Developer Aug 04 '19 at 06:45

Combine in Playgrounds

2 Answers2